464 keyboard problem

[Spoon]

Hi all I wish my 2nd post here could have been a happier one but...any advice on this will be greatly appreciated.
I bough a 464 "untested" won't be doing that again, it doesn't work just shows a white screen with a black border after I bought a scart adapter to use with it. It did come with what he said was the charger which it obviously wasn't.
I bought another which was working except the tape deck was not playing but you could here it was trying to but not turning but it would rewind and fast forward so I thought yes it's probably a slack belt. Took it apart and found the idler tyre had a chunk missing so replaced it with the idler from the none working 464 and fitted new belts, one working machine!
Anyway, Friday I was happily playing Roland in time then switched off to put another game in and when I did, the ctrl and small enter key isn't working neither is c b n m and a couple of keys on the numeric pad. So no more Roland in time until I find out if I can fix it. I know it's not the keyboard as I tried the spare keyboard and same fault with that in.
Looking through the forum there's something about bypassing by soldering wires at various points? The mechanical bit I'm OK with but electrics.. I may aswell be looking under the bonnet of a space ship. I don't mind soldering a few wires if I know where they go.
Any help would be great.
Sorry meant to post this in hardware can a moderator move it please?

[Gryzor]

No worries 

[Spoon]

So, all the keys are working except every key on connector 9 if I am looking at the keyboard diagram right..
Why would this just happen?

[Gryzor]

How is the connector ribbon?

[Spoon]

Hi, the ribbon is ok I think as I tried another keyboard with the same result. 
Someone has cut the legs 20 and 22 from the 40009 chip and soldered them with wire to the board. Ive also just noticed that legs 20 and 21 on the AY-3 seem to have had some solder applied to them aswell and there is a small chip/hole in it at the top of the leg.. one or both of these is probably whats wrong? but it was working fine before.